ALF259 Miniature Diaphragm Load Cell

Miniature diaphragm load cell with bi-directional versions, for force measurements in confined spaces

About the ALF259 Miniature Diaphragm Load Cell

The force sensor ALF259 is ideally suited to force measurements in confined spaces in both tension and compression for control of critical parameters in all kinds of industrial processes. Their versatility is such that they are also applied in a great number of important fields of scientific and engineering test work, mobile as well as workshop, static and dynamic.

Geometry: Very small loadbutton cell for force measurement in confined spaces. Used in compression and/or tension on a wide range of OEM or end-user applications.

With bi-directional versions there is a small difference between the output signal for compression and tension. All standard bi-directional loadcells are calibrated in both modes and the output for each direction is stated on the test / calibration certificate.

Application area

  • Industrial process
  • Scientific and engineering test work 


  • Miniature diaphragm loadcell
  • Measurement range: 25kg, 50kg, 100kg
  • Tension, compression and bi-directional
  • Non-lin./hysteresis: 0.5/0.5% RL
  • Dimensions (mm): Ø12.7 x 9
  • Tension / compression / bi-directional calibration
  • Easy installation
  • Hardened stainless steel body
  • Standard 2 year warranty

All standard ranges are manufactured in stainless steel.
When this loadcell is rationalised the resistors are housed in a capsule located in the loadcell cable 100mm from the free end. Capsule dimensions are Ø10mm by 57mm.

1. AL = Applied load. 3. Temperature coefficients apply over the compensated range.
2. RL = Rated load. 4. The load must be applied directly through the central loading axis.


The loadcell is fitted with 2 metres of PVC insulated 4 core screened cable type 7-1-4C.
Excitation + = Red Signal + = Yellow Screen = Orange
Excitation - = Blue Signal - = Green
Reverse the signal connections to obtain a positive signal in tension mode. The screen is not connected to the loadcell body.

We are happy to design variants of this loadcell to meet your specific requirements. Please consult our engineering department.


Measurement range
25kg, 50kg, 100kg
Non-linearity - Terminal
±0.5% RL
±0.5% RL
Creep - 20 minutes
±0.2% AL
±0.1% RL
Rated output - Nominal
Rated output - Rationalised
Load direction
Tension, compression, bi-directional
Rationalisation tolerance (applies to single direction calibrations)
±0.5% RL
Zero load output
±4% RL
Temperature effect on rated output per °C
±0.005% AL
Temperature effect on zero load output per °C
±0.03% RL
Temperature range - Compensated
-10 to +50°C
Temperature range - Safe
-10 to +80°C
Excitation voltage - Recommended
Excitation voltage - Maximum
Bridge resistance
350 Ω
Insulation resistance - Minimum at 50Vdc
500 MΩ
Overload - Safe
50% RL
Overload - Ultimate
100% RL
Weight - Nominal (excluding cable)
6 to 7.5g
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